Chapter 1. Deciphering the toxicity of Helicobacter pylori clinical isolates from gastric diseases patients using MALDI-TOF/MS and multivariate analysis.
Helicobacter pylori (H. pyloyi) infection is associated with gastric diseases such as gastric polyp, chronic gastritis, gastric ulcer, gastric cancer, etc. In fact, most of the people infected not have the symptoms of gastric diseases due to the high degree of variability of gene with H. pyloyi and the specific immune responses of the hosts. In order to investigate the relationship between H.pylori and gastric diseases, the clinical strains of H. pylori isolated from patients from nine gastric diseases were extracted from the optimized extraction and analysis by MALDI-TOF/MS, then the high reproducible spectra were combined with multivariate statistical analysis including Principal Component Analysis (PCA), Hierarchical Cluster Analysis (HCA), Discriminant Analysis (DA) . In the result of PCA, there is no specific potential marker to discriminate the clinical strains to nine gastric diseases. In the result of HCA, the strains from different gastric diseases were clustered together means they have the similarity of the protein and metabolite. In the result of DA, the strains from gastric and non-gastric cancer were discriminanted by the discriminant function composed of thirty-eight discriminant variables in the spectra. This discriminant function would be confirmed by other clinical strains isolated from gastric diseases patients in the future and then would help to predict the the similarity of the protein and metabolite of the strains isolated from the gastric diseases patients whether gastric cancer or not.
Chapter 2. Biomarker discovery in the stools of gastric cancer patients using MALDI-TOF/MS.
According to the statistics of Republic 100 years from the Department of Health, cancer was the first of the ten lesding to death. With the modern change of eatiog habbits, gastrointestinal cancer has increased steadily. Gastrointestinal cancer accompanied occult gastrointestinal bleeding, and it is commonly detected by the fecal occult blood test (FOB). FOB including Guaiac-based fecal occult-blood test and immunochemical tests. Guaiac-based fecal occult-blood tests make use of the pseudoperoxidase activity of heme, and the reagent turns blue after oxidation by oxidants or peroxidases in the presence of an oxygen donor such as hydrogen peroxide, so it would have the potential of false-positive result. Immunochemical tests, which use antibodies detect against human hemoglobin with great sensitivity, but the tests are limited by loss of hemoglobin antigenicity at room temperature and require processing in a laboratory. In order to decrease the false-positive of detecting heme and decreasing the cost of the detection against hemoglobin in stools, in the study, we ues the distill water to extract the heme (m/z 616) and hemoglobin in stools and analysis with the reflectron and linear mode of MALDI-TOF/MS.
In this study, at first, we used the stimulated stomach acid decomposing the hemoglobin to release the heme, to stimulate the gastrointestinal bleeding. Second, we used the distill water to extract the hemoglobin in stools, and detected by the linear mode of MALDI-TOF/MS, and the detection limit of MALDI-TOF/MS against hemoglobin in stool was better than the immunochemical tests. Third, the same strategy was applied to fifty-nine patients (including nineteen esophageal cancer patients, twenty gastric cancer patients and colorectal cancer patients) stools to detect heme and hemoglobin by MALDI-TOF/MS and the results were compared with the fecal occult blood test.
In the detection of heme, MALDI-TOF/MS had not detect heme, but the Guaiac-based fecal occult-blood test had detected, it would be that the stools had the oxidants (not heme) to react the reagent. In addition, MALDI-TOF/MS had detected heme, but the Guaiac-based fecal occult-blood test had no results, those cases would be catched up in the future. In the detection of hemoglobin, using immunochemical tests to be the reference index, MALDI-TOF/MS had the false-negative result might come from the complicated matrix effect of stools, so that the hemoglobin could not form the good crystalline with matrix CHCA. The false-positive results of MALDI-TOF/MS might come from the criteria of hemoglobin signal.
| Identifer | oai:union.ndltd.org:NSYSU/oai:NSYSU:etd-0806112-183556 |
| Date | 06 August 2012 |
| Creators | Leung, Yun-Shiuan |
| Contributors | Po-Chiao Lin, Jentaie Shiea, Yu-Ju Chen |
| Publisher | NSYSU |
| Source Sets | NSYSU Electronic Thesis and Dissertation Archive |
| Language | Cholon |
| Detected Language | English |
| Type | text |
| Format | application/pdf |
| Source | http://etd.lib.nsysu.edu.tw/ETD-db/ETD-search/view_etd?URN=etd-0806112-183556 |
| Rights | user_define, Copyright information available at source archive |
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